The present invention relates to a flat knitting machine with at least one needle bed and a carriage which is slidable along the needle beds and has at least one cam with needle selection device and stitch cams:
Sinking surfaces on the needle sinkers and the stitch cams position of the cam of a knitting machine determine the form and the size of a stitch. Depending on a knitting type, different stitch sizes and forms are desired. In double-surface R-R knittings, slim stitches of the finest stitch pattern are produced. This is achieved by a small sinking surface on the stitch cams. In single-surface smooth knittings, to the contrary, round stitches of the finest stitch pattern are produced. For producing these round stitches, wide sinking surfaces are required on the stitch cams, so that as many needles as possible are held simultaneously in the deepest sinking position. In this matter the tendency is reduced that the already pulled stitches are pulled from the preceding formed stitches by the produced pulling forces of substantially knit threads and thereby substantially reduce these stitches.
During high grade knitting, in the machine the stitch cams are exchanged when a new knitting must be produced with another binding type. In most cases, however needle sinkers are used which have a central sinking surface and thereby a compromise between the optimal stitch cams sinkers for R-R knitting and a single-surface smooth knitting is formed.
The form of the knitting surface can be also determined as to whether all needles are pulled simultaneously wide during sinking, or in the same needle sinking position they can be pulled differently wide.
In the patent document CH 448 358 a stitch cams is proposed which has two sinking surfaces for producing two different stitch sizes. The same needles which have a higher needle foot are sinking on one sinking surface and the needles with the lower needle feet are sinking on the different sinking surfaces. With the stitch cams, two different stitch sizes are produced, and each size ratio of the stitches are fixed relative to one another and not changeable.